Production of 3, 3, 5-trimethyl cyclohexanone



Patented?! duty 3% ifili PRODUCTION OF 3,3,5-TRIMETHYL CYCLOHEXANONE Charles E. Morrell, Westfield, Richard F. Robey, Cranford, and Lester M. Welch, Madison, N. J., assignors to Standard Oil Development Company, a corporation of Delaware No Drawing. Application June 1, 1946, Serial No. 673,898

1 Claim. 1

This invention relates to a process for the hydrogenation of aldehydes and ketones and in particular to a process for the hydrogenation of alpha-beta unsaturated aldehydes and ketones and for the dehydrogenation of saturated alcohols by hydrogen exchange between saturated alcohols and saturated or unsaturated aldehydes and ketones.

Heretofore, aldehydes and ketones and particularly alpha-beta unsaturated aldehydes and ketones have been hydrogenated by high pressure catalytic methods which require the use of high pressure equipment and substantial amounts of special hydrogenation catalysts. Dehydrogenation of saturated alcohols has been performed by well known oxidation procedures. Separate reactions have been required to dehydrogenate an alcohol and to hydrogenate an alpha-beta unsaturated or saturated aldehyde or ketone.

It has now been discovered that an aldehyde or ketone, particularly an alpha-beta unsaturated aldehyde or ketone, may be hydrogenated and a saturated alcohol may be dehydrogenated simultaneously by heating the aldehyde or ketone with the saturated alcohol.

This invention has for an object the hydrogenation of aldehydes and ketones and particularly of alpha-beta unsaturated aldehydes and ketones and the dehydrogenation of saturated alcohols in a one-step reaction.

A still further object of this invention is to simultaneously hydrogenate an aldehyde or ketone and particularly an alpha-beta unsaturated aldehyde or ketone and dehydrogenate a saturated alcohol.

Still another object of this invention is to prepare two molecules of saturated aldehyde or ketone from one molecule of an alpha-beta unsaturated aldehyde or ketone and one molecule of the corresponding saturated alcohol.

Another and further object of this invention is to prepare a saturated aldehyde or keton from an alpha-beta unsaturated aldehyde or ketone by hydrogen exchange with a saturated alcohol.

Another object of this invention is to prepare a saturated alcohol from an alpha-beta unsaturated aldehyde or ketone by hydrogen exchange with a saturated alcohol.

Still another object of this invention is to we pare a saturated aldehyde or ketone from a saturated alcohol by hydrogen exchange with an aldehyde or ketone and particularly with an alphabeta unsaturated aldehyde or ketone.

According to this invention, an aldehyde or ketone, and particularly an alpha-beta unsaturated aldehyde or ketone, is heated with a saturated primary or secondary alcohol whereby saturated aldehydes or ketones are produced. The following equations illustrate the probable course of the reaction:

Also according to this invention an aldehyde or ketone and particularly an alpha-beta unsaturated aldehyde or ketone is heated with a saturated primary or secondary alcohol whereby saturated alcohols are produced. The following equations illustrate the probable course of the reaction:

Saturated alcohols suitable to be used in this invention are primary and secondary aliphatic a1- cohols. The saturated alcohol must contain at least one hydrogen atom on the carbon atom attached to the hydroxyl group. Saturated aliphatic aldehydes and ketones are readily converted to the corresponding primary or secondary alcohols and alpha-beta unsaturated aldehydes and ketones may either be converted to the corresponding saturated aldehydes and ketones or to a corresponding saturated primary or secondary alcohol, depending upon the amount of saturated alcohol which is used to furnish the hydrogen which adds to the unsaturated aldehyde or ketone.

When the alcohol and alpha-beta unsaturated aldehyde or ketone yield the same aldehyde or ketone, a different saturated alcohol will not be produced from the unsaturated aldehyde or ketone because the alcohol produced by hydrogenation of the aldehyde or ketone would in this case be identical with the alcohol furnishing the hydrogen. An example of this is the conversion of isophorone and trimethyl cyclohexanol to trimethyl cyclohexanone. Secondary saturated alcohols are preferred to primary saturated alcohols since they more readily enter into the hydrogen exchange reaction whereby hydrogen is added to an aldehyde or ketone. A lower molecular weight primary or secondary alcohol readily exchanges hydrogen to hydrogenate a saturated or unsaturated aldehyde or ketone having a, higher molecular weight than the alcohol to the corresponding saturated, aldehyde or ketone or'to the corresponding saturated primary or secondary alcohol.

The invention is applicable broadly to alphabeta unsaturated aldehydes or ketones, and examples of such aldehydes or ketones are isophorone. mesityl oxide and crotonaldehyde.

A catalyst may be used to increase the yield of reaction products and satisfactory catalysts have been found to be the class of catalyst known as hydrogenation catalysts, examples of which are Raney nickel, nickel on kieselguhr, copper and chromium oxides and catalysts containing iron and manganese.

The reaction temperature should be within the range of 100 to 400 C. The reaction may be carried out in either the gas phase or liquid phase. Hydrogen may be introduced into the reaction chamber for the purpose of maintaining the catalyst at a high levelof activity. The purpose of the introduction of hydrogen is principally to maintain the catalyst in an active condition. In general, the amount of hydrogen found satisfactory to maintain a high level of activity in the catalyst is from t; to /2' of the moles of reactants present in the reaction vessel. In any case, the amount of hydrogen to be introduced into the reaction mixture in order to maintain the activity of the catalyst should be a quantity substantially less than one mole for each mole of the carbonyl compound to be saturated.

The process representing this invention is valuable in that it accomplishes the simultaneous dehydrogenation of an alcohol and the hydrogenation of an aldehyde or ketone. The products of the reaction are valuable as intermediates for the preparation of other organic compounds and have themselves a wide variety of uses.

Example 80 grams of 3,3,5-trimethyl cyclohexanol and 75 grams of isophorone were placed in a hydrogenation bomb with grams of Raney nickel and heated at 150-200 C. for twelve hours. The temperature was allowed to come to that of the room and the reaction mixture was filtered from the catalyst and distilled. 115 grams of 3,3,5-trimethyl cyclohexanone were recovered. This represents 74% of the theoretical for complete 4 conversion of the cyclohexanol and isophorone to cyclohexanone.

This invention contemplates the conversion of a simple saturated alcohol such as isopropyl alcohol to a higher alcohol such as methyl isobutyl carbinol or higher 'ketone such as methyl isobutyl ketone in a continuous manner.

This invention contemplates the continuous preparation of a saturated aldehyde, ketone or saturated alcohol which results from the hydrogenation of a corresponding alpha-beta unsaturated aldehyde or ketone prepared by the condensation of at least two molecules of the aldehyde or ketone corresponding to the primary alcohol used in the hydrogen exchange reaction.

A specific embodiment of a continuous practice of the invention is represented by the preparation of methyl isobutyl ketone or methyl isobutyl alcohol from isopropyl alcohol and is accomplished by continually adding isopropyl alcohol and continually adding the condensation product of acetone, i. e., mesityl oxide to a reaction chamber wherein mesityl oxide is converted by hydrogen exchange with isopropyl alcohol into methyl isobutyl ketone or methyl isobutyl alcohol and wherein isopropyl alcohol is dehydrogenated to yield acetone. The products of the conversion are continually added to a distillation system wherein acetone is separated from methyl isobutyl ketone or methyl isobutyl alcohol and continually introduced into a condensation reaction chamber wherein acetone is condensed to give mesityl oxide. By this continuous process a simple saturated ketone is converted to a higher alcohol or ketone.

If ethyl alcohol and its condensation product, crotonaldehyde, are used instead of acetone and mesityl oxide in the continuous practice of the invention, the products of the reaction are butyraldelwde or butyl alcohol.

The continuous process may be practiced so that the final product is either an aldehyde, a ketone or the alcohol which results from two molecules of the alcohol yielding hydrogen to one molecule of unsaturated aldehyde or ketone. This is accomplished by adjusting the ratio of alcohol to unsaturated aldehyde or ketone; where the ratio is equimolar, the product is a saturated aldehyde or ketone, but where the ratio is two to one, the product is a saturated alcohol.

It is understood that this invention is not to be limited to the foregoing material in the nature of examples, but is to be considered broadly as defined by the language of the appended claim.

What is claimed is:

A process for hydrogenating isophorone to produce 3,3,5-trimethyl cyclohexanone therefrom, which comprises forming a mixture consisting essentially of isophorone and 3,3,5-trimethyl cyclohexanol in about equi-molar amounts, heating the resulting mixture substantially free of other reactive substances in the presence of a, nickel contact hydrogenation catalyst at reaction temperatures of about C. to 200 C., and recovering as a main resulting reaction product 3,3,5-trimethyl cyclohexanone formed by transfer of hydrogen to the isophorone and by the transfer of hydrogen from the 3,3,5- trimethyl cyclohexanol in said mixture.

CHARLES E. MORRELL. RICHARD F. ROBEY. LESTER M. WELCH.

(References on following page) REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS OTHER REFERENCES Adkins: Journ. Amer. Chem. 800., vol. 63, pages 238183 (1941).

Beilstein: Organishe Chemie, Vol. VII, page 30, Berlin, 1925. 1

Adams et 211.: Organic Reactions, vol. 11, pages 180, 181, 182, 213, 221, 222, 223. Published 1944 by John Wiley & Sons, New York.

Number Name Date 7 2,066,496 Taylor Jan. 5, 1937 2,088,015 Wickert; 1 July 27, 1937 2,156,217 Andrews Apr. 25, 1939 2,407,291 Quattlebaum et a1. Sept. 10, 1946 10' 

